酵母菌C10产菊粉酶酶学性质的研究

Study on the enzymatic properties of inulinase produced by yeast C10

采用菊粉酶活力测定的方法研究了酵母菌C10所产菊粉酶的酶学性质。该酶的最适温度和最适pH分别为50℃,5.5。在此条件下,该酶酶活力达到12.0U/mL,I/S值为14.0,其水解菊粉后低聚糖得率为29%。1.5%菊芋干粉为合成菊粉酶较好的诱导物;Mn2+,Ca2+,Mg2+对菊粉酶有激活作用,Zn2+,Cu2+,Fe2+有抑制作用。该菊粉酶中胞外酶,胞壁酶,胞内酶分布为7.5∶0.5∶2.0。研究了底物浓度对酶反应的影响,当底物浓度达到20mg/mL时,产物浓度基本不变,反应初速度达到最大值。

The enzymatic properties of inulinase produced by yeast C10 were investigated with assays of inulinase activity. The results showed the optimum temperature and pH of inulinase were 50℃ and 5.5 respectively. The value of enzymatic activity was 12.0U/mL, I/S was 14.0, and the rate of fructooligosaccharides' production was 29%. The better inducer was chicory powder with concentration at 1.5%. Mn^(2+),Ca^(2+),Mg^(2+) can activate the inulinase, but Zn^(2+),Cu^(2+),Fe^(2+) inhibit it.The ratio of exoinulinase, extracellular inulinase ,endoinulinase was 7.5∶0.5∶2.0. When substrate concentration attained 20mg/mL,resultant concentration remained unchanged, and initial velocity attained maximal value.